For example, at the time of transfusion of a high-concentration pabulum into a patient, an indwelling needle including a catheter (outer needle) and a piercing needle (inner needle) is made to pierce the patient, the piercing needle is evulsed with the catheter left in a pierced state, a guide wire is inserted through the catheter to reach a blood vessel (vein) near the heart, the catheter is evulsed, a central arterial catheter is inserted along the guide wire into the blood vessel, the guide wire is removed so that only the central arterial catheter is left indwelling in the pierced state, a transfusion line through which a pabulum, a medicinal liquid, or the like is supplied is connected to the central arterial catheter, and a transfusion is conducted.
In the case that such an indwelling needle is made to pierce a blood vessel, for example, ultrasonic waves are emitted from an ultrasonic imaging device, thereby confirming the position of the blood vessel to be pierced. In addition, the piercing needle, which is in the pierced state, is irradiated with ultrasonic waves, and a surgical procedure is carried out while confirming the position of the piercing needle through an image obtained based on the reflected waves.
Hitherto, as such an indwelling needle, indwelling needles in which an outer circumferential surface of a piercing needle (inner needle) is provided with a helical groove or a V-shaped groove in a recessed form have been known (see, for example, Japanese Patent No. 3171525 and Japanese Laid-Open Patent Publication No. 03-228748). Upon using this type of indwelling needle, the piercing needle is made to pierce a diseased part of a patient, the pierced part is irradiated with ultrasonic waves emitted from an ultrasonic imaging device, whereupon the ultrasonic waves are reflected by an air layer in the helical groove or the V groove, and the reflected waves are received by the ultrasonic imaging device in order to obtain a picked-up image (echo image) of the piercing needle.